Population genetics to understand the mechanisms of Xylella pathogenesis to inform novel control measures

Summary: The plant pathogen Xylella fastidiosa has recently been brought to global attention due to multiple disease outbreaks in mainland Europe. X. fastidiosa is one of the most harmful bacterial plant pathogens in the world, which can infect an extensive range of woody and herbaceous plants. This project will aim to understand the genetic mechanisms of infection in different hosts and subsequently develop novel control measures. The pathogen is highly transmissible as it is vectored by an unknown number of xylem-feeding insects. In addition, infections can be asymptomatic, where the plant shows no visible symptoms. This makes trade of host species a serious transmission threat. When it does cause disease, symptoms consist of stunting, wilting, and subsequent death, leading to large yield losses. Although X. fastidiosa has not been reported in the UK, it is an enormous threat, as crops such as Prunus (cherries, almonds) and ornamental species are known hosts.  At present, there are no available control measures, and management strategies consist of the removal of infected material and restricted plant movement within a 10km radius. Xylella could therefore be devastating to UK horticulture.

This project will involve detection and identification of X. fastidiosa in distinct locations and plant hosts gathered from around Europe. New sequencing tools will be used to compare asymptomatic and pathogenic infections, to identify factors involved in pathogenicity. This will inform the development of highly specific control measures, involving molecules that target and disrupt pathogenic factors, thus reducing the ability of X. fastidiosa to cause disease.